The International Commission on Radiation Units and ...

1 The International Commission on Radiation Units andMeasurementsIntroductionThe International Commission on Radiation Unitsand Measurements (ICRU), since its inception in1925, has had as its principal objective the develop-ment of internationally acceptable recommendationsregarding:(1) quantities and Units of Radiation and radioactivity,(2) procedures suitable for the measurementand application of these quantities in clinicalradiology and radiobiology, and(3) physical data needed in the application of theseprocedures, the use of which tends to assureuniformity in Commission also considers and makes similartypes of recommendations for the Radiation protec-tion field.

2 In this connection, its work is carriedout in close cooperation with the InternationalCommission on Radiological Protection (ICRP).PolicyThe ICRU endeavors to collect and evaluatethe latest data and information pertinent to theproblems of Radiation measurement and dosimetryand to recommend the most acceptable values andtechniques for current Commission s recommendations are keptunder continual review in order to keep abreast ofthe rapidly expanding uses of ICRU feels that it is the responsibility ofnational organizations to introduce their owndetailed technical procedures for the developmentand maintenance of standards.

3 However, it urgesthat all countries adhere as closely as possible tothe internationally recommended basic concepts ofradiation quantities and Commission feels that its responsibility liesin developing a system of quantities and Units havingthe widest possible range of applicability. Situationscan arise from time to time for which an expedientsolution of a current problem might seem speaking, however, the Commission feelsthat action based on expediency is inadvisablefrom a long-term viewpoint; it endeavors to baseits decisions on the long-range advantages to ICRU invites and welcomes constructivecomments and suggestions regarding its rec-ommendations and reports.

4 These may be trans-mitted to the ProgramThe Commission recognizes its obligation toprovide guidance and recommendations in the areasof Radiation therapy, Radiation protection, and thecompilation of data important to these fields, and toscientific research and industrial applications ofradiation. Increasingly, the Commission is focusingon the problems of protection of the patient andevaluation of image quality in diagnostic activities do not diminish the ICRU s commit-ment to the provision of a rigorously defined set ofquantities and Units useful in a very broad range ofscientific Commission is currently engaged in theformulation of ICRU Reports treating the followingsubjects.

5 Approaches to the Dosimetry of Low-Dose Exposuresto Ionizing RadiationDesign of a Voxel Phantom for Radiation ProtectionDose and Volume Specifications for ReportingIntra-Cavity Therapy in GynecologyDoses from Cosmic-Ray Exposures of AircrewFundamental Quantities and UnitsHarmonization of Reporting Patient Diagnostic DosesImage Quality and Patient Dose in ComputedTomographyKey Data for Measurement Standards in theDosimetry of Ionizing RadiationPrescribing, Recording, and Reporting Ion-BeamTherapyThe Commission continually reviews radiationscience with the aim of identifying areas in whichJournal of the ICRU Vol 10 No 1 (2010) Report 83 University Press# International Commission on Radiation Units and Measurements 2010 at Masaryk University on September 17, from the development of guidance and recommendationscan make an important ICRU s Relationship with OtherOrganizationsIn addition to its close relationship with the ICRP,the ICRU has developed relationships with otherorganizations interested in the problems of radiationquantities, Units , and measurements.

6 Since 1955,the ICRU has had an official relationship with theWorld Health Organization (WHO), whereby theICRU is looked to for primary guidance in mattersof Radiation Units and measurements and, in turn,the WHO assists in the worldwide dissemination ofthe Commission s recommendations. In 1960, theICRU entered into consultative status with theInternational Atomic Energy Agency (IAEA).The Commission has a formal relationship with theUnited Nations Scientific Committee on the Effectsof Atomic Radiation (UNSCEAR), whereby ICRU observers are invited to attend annual UNSCEAR meetings. The Commission and the InternationalOrganization for Standardization (ISO) informallyexchange notifications of meetings, and the ICRU isformally designated for liaison with two of the ISOtechnical committees.

7 The ICRU also enjoys astrong relationship with its sister organization, theNational Council on Radiation Protection andMeasurements (NCRP). In essence, these organiz-ations were founded concurrently by the same indi-viduals. Presently, this long-standing relationship isformally acknowledged by a special liaison agree-ment. The ICRU also corresponds and exchangesfinal reports with the following organizations:Bureau International de Me trologie Le galeBureau International des Poids et MesuresEuropean CommissionCouncil for International Organizations of MedicalSciencesFood and Agriculture Organization of the UnitedNationsInternational Committee of PhotobiologyInternational Council for ScienceInternational Electrotechnical CommissionInternational Labor OrganizationInternational Organization for Medical PhysicsInternational Radiation Protection AssociationInternational Union of Pure and Applied PhysicsUnited Nations Educational.

8 Scientific and CulturalOrganizationThe Commission has found its relationship withall of these organizations fruitful and of substantialbenefit to the ICRU FundsIn recent years, principal financial support hasbeen provided by the European Commission , theNational Cancer Institute of the US Department ofHealth and Human Services, and the InternationalAtomic Energy Agency. In addition, during the last10 years, financial support has been received fromthe following organizations:American Association of Physicists in MedicineBelgian Nuclear Research CentreElectricite de FranceHelmholtz Zentrum Mu nchenHitachi, Radiation Protection AssociationInternational Society of RadiologyIon Beam Applications, Society of Radiological TechnologyMDS NordionNational Institute of Standards and TechnologyNederlandse Vereniging voor RadiologiePhilips Medical Systems, IncorporatedRadiological Society of North AmericaSiemens Medical SolutionsVarian Medical SystemsIn addition to the direct monetary support pro-vided by these organizations.

9 Many organizationsprovide indirect support for the Commission sprogram. This support is provided in many forms,including, among others, subsidies for (1) the timeof individuals participating in ICRU activities,(2) travel costs involved in ICRU meetings, and(3) meeting facilities and recognition of the fact that its work is madepossible by the generous support provided by allof the organizations supporting its program, theCommission expresses its deep MenzelChairman, ICRUG eneva, SwitzerlandPRESCRIBING, RECORDING, AND REPORTING PHOTON-BEAM IMRT at Masaryk University on September 17, from Prescribing, Recording, and Reporting Photon-BeamIntensity-Modulated Radiation Therapy (IMRT) Summary.

10 51 Introduction .. Overview of Intensity-Modulated Radiation Therapy (IMRT) .. From Three-Dimensional Conformal (3D-CRT) to Intensity-Modulated RadiationTherapy .. Delivery of IMRT .. Clinical Experience with IMRT .. Issues Common to Both 3D-CRT and IMRT .. Imaging and 4D Adaptive Treatment .. Margins and Uncertainties .. Radiation -Induced Secondary Cancers .. Aim of the Present Report and Relation to Existing ICRU Reports ..152 Optimized Treatment Planning For IMRT .. Introduction .. Comparison of 3D-Conformal and IMRT Treatment Planning .. Overview of the Optimization Process.